Cars are equipped with a wiper device for wiping a surface of a windshield. Typically, the wiper device includes a driving motor, a wiper arm and a wiper blade positioned on the surface of the windshield.
The driving motor functions to produce a reciprocal movement. The wiper arm is coupled to a rotating shaft of the driving motor at its base end. The wiper blade is detachably joined to a distal end of the wiper arm. A component for biasing the distal end of the wiper arm toward the windshield is provided at the distal end of the wiper arm. Thus, the wiper blade becomes closed to the surface of the windshield under the biasing force of the wiper arm and wipes out the windshield surface while sliding thereon by reciprocating pivoting motions caused by the driving motor.
The wiper blade typically has an elongated wiping strip brought into contact with the windshield surface and a frame component for attaching the wiping strip therealong and supporting the same thereon. The frame component may include an assembly having a plurality of levers.
A wiper blade, which uses a single frame having a flat and elongated bar shape as the frame component, has been recently used. Such a wiper blade is known in the art as “a flat wiper blade” or “a flat bar wiper blade.” The flat wiper blade not only lowers an entire height of a wiper device, but also has its wiping strip contact the windshield surface under a uniform or consistent load.
The flat wiper blade may be connected to the wiper arms via a connecting device, which is installed to a middle section of the frame. The connecting device is designed to be suitable for a distal end of a wiper arm. Manufacturers of wiper arms have put their own inherent wiper arms for flat wiper blades in the market. Also, the manufacturers of wiper arms or the manufacturers of wiper devices have put various connecting devices, which are configured to be suitable for the flat wiper arms, in the market. Accordingly, there have been known in the art various wiper arms for flat wiper blades and various connecting devices adapted for wiper arms.
FIGS. 1 to 6 illustrate examples of various conventional wiper arms for flat wiper blades.
Wiper arms 1, 1′ shown in FIGS. 1 and 2 are configured such that their distal ends have a receiving section, concave portions provided at a rear side of the receiving section and a tongue protruding from a front side of the receiving section. These wiper arms are known in the art as “a top lock wiper arm” or “a pinch tab wiper arm.” Korean Patent Application Laid-Open Publication No. 10-2005-0085129 and Korean Patent Application Laid-Open Publication No. 10-2005-0007446 disclose a connection example between a flat wiper blade and a top lock wiper arm, wherein a connecting device supports the tongue and is snap-engaged to the concave portions.
A wiper arm 2 shown in FIG. 3 is configured such that its distal end has a shape of a hook. This wiper arm is known in the art as “a hook wiper arm.” A hook wiper arm is also used for a wiper blade including a frame component comprising a lever assembly. Korean Patent Application Laid-Open No. 10-2005-0033046 discloses a connection example between a flat wiper blade and a hook wiper arm, wherein the hook part provided at the distal end of the wiper arm 2 and a connecting device are joined by an elastic engagement therebetween.
A wiper arm 3 shown in FIG. 4 is configured such that its distal end defines an insertion space. This wiper arm is known in the art as “a bayonet wiper arm.” Korean Patent No. 10-725988 discloses a connection example between a flat wiper blade and a bayonet wiper arm, wherein a connecting device is fitted to the insertion space to be jointed to the wiper arm.
A wiper arm 4 shown in FIG. 5 is configured such that its distal end portion has a side pin and a clip arm protruding to the wiper arm 4. This wiper arm is known in the art as “a side pin wiper arm,” “a side lock wiper arm” or “a slide pin wiper arm.” Korean Patent Application Laid-Open Publication No. 10-2008-0059225 discloses a connection example between a flat wiper blade and a side lock wiper arm, wherein the side pin 41 passes through a tubular component of a connecting device and the clip arm 42 is snap-engaged to the connecting device.
A wiper arm 5 shown in FIG. 6 is configured such that its distal end has a pin 51 perpendicularly protruding therefrom and a circumferential groove 52 formed in the pin 51. This wiper arm is known in the art as “a pin wiper arm.” A pin wiper arm is also used for a wiper blade including a frame component comprising a lever assembly. The pin wiper arm may be joined to a connecting device by an engagement between the pin 51, the circumferential groove 52 and the connecting device.
As discussed above, wiper arms 1, 1′, 2, 3, 4, 5 illustrated in FIGS. 1 to 6 may be connected to a flat wiper blade when only using a connecting device configured to be suitable for the shape of the distal end of each wiper arm. That is, various types of connecting devices must be prepared according to the shapes of distal ends of wiper arms. As a result, there must be different connecting devices, each of which is only suitable for a specific shape of one wiper arm.
Further, the manufacturers of such connecting devices must design and develop various different connecting devices, each of which is suitable for only one wiper arm. This is clearly disadvantageous in that the number of parts constituting connecting devices is large, thereby causing difficulties in development and maintenance while increasing manufacturing and distribution costs. On the other hand, users or consumers must choose a specific connecting device, which is configured to be suitable for a distal end of a wiper arm equipped to their own cars. This is also disadvantageous since they would have difficulty and inconvenience in choosing the right connecting device. Accordingly, there is a need to provide a connecting device for a flat wiper blade and wiper arms, which can be applied to various types of wiper arms.
Further, in case of conventional connecting devices disclosed in Korean Patent Application Laid-Open Publications Nos. 10-2005-0085129 and 10-2005-0007446, a pair of elongated bar-shaped parts of the connecting devices are snap-engaged to the concave portions 14a, 14b, 14a′, 14b′ of the wiper arm 1, 1′. However, the engagement between those bar-shaped parts and the concave portions can become loose due to the configuration of the bar-shaped parts. That is, when a flat wiper blade is reciprocally driven by a wiper arm, the bar-shaped parts can be curved inwardly of the flat wiper blade, thereby causing a problem between the bar-shaped parts and the concave portions while failing to provide a tight engagement therebetween. In addition, since the bar-shaped parts protrude backwardly of the connecting device, the bar-shaped parts can be bent and broken during transportation or assembly.
Further, in case of the conventional connecting device disclosed in Korean Patent Application Laid-Open Publication No. 10-2008-0059225, a side pin 51 fails to smoothly pivot relative to the connecting device. Thus, a flat wiper blade cannot be placed in close contact with the surface of the windshield while conforming to the curvature of the windshield surface.
As discussed above, there is a problem with conventional connecting devices in that a firm coupling is not accomplished between a flat wiper blade and a wiper arm. Further, a smooth pivoting motion of a flat wiper blade cannot be provided. Accordingly, there is a clear need to provide a connecting device, which provides smooth pivoting of a flat wiper blade while firmly coupling the flat wiper blade to the wiper arm.